Breast cancer is the leading cancer type in women. Women who are at greatest risk for developing breast cancer and who are least likely to complete monthly breast self-examination are those ages 35 and over. Research has shown that monthly breast self-examination allows discovery of breast cancer at a more clinically favorable stage. The proposed research will utilize variables found to be significantly related to the older women's performance of breast self-examination in the development of nursing interventions to improve this important health behavior. Research will be guided by theories related to health behaviors and by results from past research. Variables will include attitudes towards breast cancer and breast self-examination, interventions developed to increase the behavior of breast self examination, knowledge about breast cancer and breast examination, personal experience with breast cancer among family and friends, confidence in detecting breast lumps, social influences, demographic variables, and intention, frequency, and proficiency of breast self-examination. Major objectives of this study include: (1) Description of attitudinal beliefs, social influences, demographic variables, knowledge about breast cancer and breast self-examination, personal experiences, intention, frequency, and proficiency of breast self-examination in a population of women 35 and over; (2) Identification of the relationship of attitudinal variables, social support, self efficacy, demographic variables and personal experience to intention, frequency, and proficiency of breast self-examination; (3) Measurement of the effect of interventions based upon attitudinal variables and teaching strategies in predicting intention, frequency, and proficiency for breast self-examination. A 2 X 2 factorial design will be utilized with participants randomly assigned to one of four groups. Group one will include no intervention, groups two, three and four will include interventions based on past research. Subjects will be a probability sample of 600 women aged 35 and over selected via random digit dialing. Multivariate and univariate analyses will be employed to test hypotheses under the objectives which will indicate the contribution of all variables to frequency, intention and proficiency of breast self-examination. Conclusions of this study will be used for the development of nursing interventions to increase breast self-examination in women 35 and over.